A Langereis

Measurements of absolute transition probabilities in Ba ii through optical nutation: erratum

We have developed a method to measure absolute transition probabilities for ions by recording optical nutation. Ions in an accelerated beam are brought into resonance with a counterpropagating laser beam by a rapid Doppler switch. From the time evolution of the population of the upper level in the resonant transition, we determine the Rabi frequency of the transition. An accurate measurement of the electric field strength then yields the transition probability. We report measurements for five transitions in Ba ii. For three of these transitions our values are more accurate than those of earlier published results.

Collision-based spectroscopy of Xe viii Rydberg states

The photon emission from 60-keV Xe6+ colliding with Na or Ar was recorded in the 35–800-nm wavelength region. Several of the observed lines were classified as transitions from singly excited states in Xe5+. The dipole polarizability of Xe6+ and the ionization energy of Xe5+ were determined from a fit with the polarization formula to the experimentally determined energy levels of nonpenetrating states. The analysis was assisted by Hartree–Fock calculations. All Xe5+ lines in the range 35–800 nm, reported in this work or previously, are tabulated.The photon emission from 60-keV Xe6+ colliding with Na or Ar was recorded in the 35–800-nm wavelength region. Several of the observed lines were classified as transitions from singly excited states in Xe5+. The dipole polarizability of Xe6+ and the ionization energy of Xe5+ were determined from a fit with the polarization formula to the experimentally determined energy levels of nonpenetrating states. The analysis was assisted by Hartree–Fock calculations. All Xe5+ lines in the range 35–800 nm, reported in this work or previously, are tabulated.

Absolute rates for radiative and non-radiative collisional deexcitation of metastable He+ (2s) in targets of variable polarizability

A method devised to measure separate absolute rates for deexcitation of metastable hydrogenic atoms and ions via radiative (R) and non-radiative (NR, e.g. Penning ionization (PI)) processes has fir ...

Photon spectroscopy of slow Heq+ + He (q = 1,2) collisions

Abstract Photon emission following slow ion-atom collisions has been observed for the collision systems Heq+ + He(q = 1,2) at the energy 10 keV q−1. In particular relative photon emission cross sections for the 1 s 2 1 S 0 −1s n p 1 P 1 series in neutral helium are reported for both charges of the incoming helium ion. The work has been performed at the Uppsala University ECR ion source facility.

Observation of frequency beats in optical nutation due to magnetic substate degeneracy

Abstract The effects of magnetic substate degeneracy on optical nutation has been studied with a rapid Doppler shifting technique in collinear laser spectroscopy on ion beams. We excite five transitions with both linear and circular polarizations, and observe frequency beats due to the present of several Rabi frequencies. A fully quantum mechanical model has been developed to provide a theoretical comparison with the experiment. The recorded nutation patterns are well reproduced by this model. To our knowledge this is the first observation of frequency beats in optical nutation due to a mixture of Rabi frequencies.

Transition probabilities in Sm II via optical nutation

We have measured the transition probabilities for three lines in Sm II. The measurements are made by studying optical nutation with a fast Doppler switching technique in collinear laser spectroscopy on ion beams. The recorded nutation curves are fitted to a quantum-optical theoretical model, and the transition probabilities are extracted. For all three lines, the measured transition probabilities are more accurate than those of earlier published measurements.